Rick Anderson has written a review of one alternative to Beall’s List: the subscription resource Cabell’s Predatory Journal Blacklist.
Overall, I find the Cabell’s Blacklist product to be a carefully crafted, honestly managed, and highly useful tool for libraries, faculty committees, and authors.
Anderson, R. (2018). Cabell’s Predatory Journal Blacklist: An Updated Review. The Scholarly Kitchen. https://scholarlykitchen.sspnet.org/2019/05/01/cabells-predatory-journal-blacklist-an-updated-review/